Comparison of cell adhesion molecule expression between glioblastoma multiforme and autologous normal brain tissue

We investigated glioblastoma multiforme (GBM) for a pattern of consistent alterations in cell adhesion molecules (CAM) expression that might distinguish tumor from normal autologous brain tissue. We used frozen section immunohistochemistry with anti-CAM and computerized image analysis to quantify staining intensity which we expressed as relative intensity units (RIU). Our results showed that normal brain tissue generally did not express α₁β₁, intercellular CAM-1 (ICAM-1), and sialylated Lewis^x, slightly expressed α₂, α₄, α₅, α₆β₁, α_vβ₃, lymphocyte function-associated antigen-3 (LFA-3), Lewis^x, sialylated LewisLewis^x, had a good expression of α₃β₁ rmand CD44, and strongly expressed neural CAM (NCAM). GBM expressed α₁, α,₃ α₅, α₆β₁, α_vβ₃, ICAM-1, LFA-3, CD44, Lewis^x, sialylated Lewis^x, and sialylated LewisLewis^x significantly higher (2-11-fold RIU) than normal brain tissue. ICAM-1 and LFA-3 were the most distinctive markers of GBM. The small blood vessel endothelial cells of the normal brain and the GBM showed a few differences. The tumor endothelium expression of α₂β₁, α₄β₁, and LFA-3 RIU appeared twice higher than in normal endothelium and α₆β₁ showed an average of 40% RIU decrease in comparison to normal. These results show that the expression of several CAM is consistently altered in GBM and its microvasculature when compared with autologous normal brain tissue.